沈抚新城地下水中PAHs的污染特征及健康风险评价

为了保障浑河流域处于正在进行城镇化沈抚新城居民的生活用水安全,采集该地区49个地下水样品对16种US EPA优控的多环芳烃(PAHs)进行了分析,并对PAHs的污染水平、空间分布、来源与饮水健康风险进行了调查与评估.结果表明:49个采样点均有不同程度的PAHs检出,地下水中PAHs的浓度范围为(4.38~2 005.02 ng·L~(-1)),平均浓度值为(414.64±526.13) ng·L~(-1),与国内外其他地区地下水对比,处于较高污染水平.地下水中PAHs主要以3环和4环为主,其平均浓度分别为(190.93±238.96) ng·L~(-1)和(140.01±234.69) ng·L~(-1),两者占总PAHs含量的80%.枯水期的地下水中PAHs空间分布受土地利用类型影响较大,当表层土壤为耕地时,地下水PAHs浓度较大,而为林地时PAHs浓度较小.由主成分分析-多元线性回归结果得知,地下水中PAHs主要来源于汽油和天然气的不完全燃烧、煤炭燃烧、石油泄漏以及交通排放,其贡献率依次为36.26%、32.72%、28.17%和2.87%.不同人群通过饮用地下水暴露于PAHs的终生致癌风险ILCR值范围为5.55×10-10~5.65×10-6,其中13.60%的值处于10-6~10-4之间,具有潜在的癌症风险,需引起对地下水质量的关注.

Pollution Characteristic and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Groundwater of Shen-Fu New City in the Hunhe River Basin

To protect the safety of water used by the residents in Shen-Fu New City, which is undergoing the process of urbanization, 49 groundwater samples were collected along the Hunhe River Basin and 16 US EPA priority control polycyclic aromatic hydrocarbons (PAHs) were analyzed. The occurrence, distribution characteristics, sources, and potential health risk of drinking the groundwater were also assessed in this study. The results show that PAHs were detected in all samples. The concentration of PAHs ranges from 4.38 to 2005.02 ng·L^-1, with an average value of (414.64±526.13) ng·L^-1. Based on the comparison of the concentration level with that of other regions, the results in this study indicate a higher pollution level. The 3-4 ring PAHs are dominant; the average value was (190.93±238.96) ng·L^-1 and (140.01±234.69) ng·L^-1, respectively, accounting for 80% of the total PAHs. The distribution of PAHs in the groundwater is affected by the land use types. The concentration of PAHs is higher when the land use type is cultivated land, while it is lower when it is forest land. The source of PAHs was identified using Principal Component Analysis-Multiple Linear Regression (PCA-MLR). It was revealed that 36.26% of the PAHs are due to incomplete combustion of petroleum and gas, 32.72% are due to coal combustion, 28.17% originate from petroleum spills, and 2.87% are due to traffic emissions. The cancer risk levels releated to drinking the groundwater range from 5.55×10^-10 to 5.65×10^-6 and 13.60% of the values is in the range of 10^-6-10^-4. The levels are higher than the baseline of the acceptable risk, indicating the potential cancer risk. More attention should be paid to the quality of the groundwater.